There has been known a hybrid vehicle including a drive motor and an engine, wherein the engine is started by utilizing torque of the drive motor (see JP-A-2012-081875, for example).
In such a hybrid vehicle, generally, torque for starting the engine is secured as reserve torque during EV travelling by the drive motor. Therefore, an EV travelable range is a torque area obtained by subtracting the reserve torque from the original maximum torque which the drive motor can output.
FIG. 15 is a torque characteristic diagram of a motor in which torque of the motor is shown along a vertical axis and a rotational speed of the motor is shown along a horizontal axis. When the maximum torque of the motor is set to A (Nm) and the maximum output is set to B (kW), and further the starting torque (ENG starting reserve torque) necessary for starting an engine is set to Y (Nm) or the starting output is set to S (kW), an EV travelable range is limited to a region (EV travelable range) where the torque of the motor is A−Y (Nm) or less or the output is B−S (kW).
In recent years, it is required to extend an EV travelable range from the demand for improving fuel efficiency and the like.